1. Field of the Invention
The present invention relates to a device for allowing the use in an aircraft of at least one personal radiocommunication means.
Although the present invention is more particularly appropriate to a mobile telephone, that is to say to a self-contained telecommunication device based on communication techniques used by cellular networks, it can also be applied to other radiocommunication means, such as for example portable computer terminals. In a known manner, such portable terminals make it possible to effect a computer communication, by virtue of their connection to computer networks with the aid of built-in radio modems.
2. Description of the Related Art
It is known that mobile telephones, whose numbers have greatly increased in a short space of time, on account of reduced purchase price and affordable communication costs, are prohibited from use on board aircraft, especially civil transport aircraft, for safety reasons. This prohibition is in fact necessary in order to avoid any electromagnetic interference with electronic systems on board the aircraft, which may occur because the radiocommunication means necessarily operates at high power so that it can be picked up from outside, such interference possibly being, of course, very damaging, in particular during the takeoff and landing of the aircraft.
Additionally, when the passengers of a transport aircraft wish to communicate with their usual contacts, they have to use communication systems provided, if relevant, for this purpose on the aircraft.
Thus, as regards for example telephone communications, specific handsets with which aircraft are generally equipped are often made available to passengers to allow them to call the subscribers of the terrestrial telephone network.
The means of radiocommunication employed for this purpose use:
either geostationary satellites; PA1 or radiocommunication installations provided on the ground and intended for air transport. PA1 communication means which use ground installations have only limited geographical coverage. Moreover, since several communication systems of different types are in existence, various appropriate items of equipment are necessary on the aircraft to obtain a satisfactory communication field; and PA1 communication means which use geostationary satellites do not have worldwide coverage (the polar regions are, for example, not covered) and the limited number of available channels reduces the communication capacities. PA1 at least one first antenna able to transmit and pick up, outside the aircraft, electromagnetic waves respectively picked up and transmitted by satellite networks or ground networks, called outside networks; PA1 at least one second antenna able to transmit and pick up, inside the aircraft, electromagnetic waves respectively picked up and transmitted by a passenger's radiocommunication means; and PA1 a transponder which comprises : PA1 act, by way of said second transmission and reception system and said second antenna, if relevant on a power auto-matching system built into said radiocommunication means; and/or PA1 are built into said central unit, thus making it possible to simplify the device in accordance with the invention.
Moreover, specific installations have to be set up on the ground in order to cooperate with these radiocommunication means, and especially to transmit telephone communications to the persons called.
On the other hand, it is not possible for a subscriber located on the ground to call a passenger in the aircraft, in particular on account of complex procedures for transmitting a call to said passenger on board the aircraft.
The aforesaid solutions are therefore unsatisfactory, especially since they use complex and expensive installations intended first and foremost for air transport, thus entailing an extremely high communication cost.
Moreover, these solutions have the following drawbacks: